The report by Sean Guerin, the Government-appointed senior counsel, into claims made by a whistleblower Sgt Maurice McCabe alleging serious wrongdoing by Garda members, raises major concerns about how the criminal justice system operates. One alarming feature highlighted in the report was the passive role adopted by the Department of Justice and its former minister, Alan Shatter, in handling Sgt McCabe’s large dossier of complaints. Mr Guerin found that neither the Department nor the Minister took the whistleblower’s allegations seriously – despite his long experience of policing and impressive record of service in the force.

Mr Guerin put it bluntly: “In effect, the process of determining Sgt McCabe’s complaints went no further than the Minister receiving and acting upon the advice of the person who was the subject of the complaint.” Both the Department and the Minister, it seems, readily accepted – without ever challenging – the explanations that senior Garda management offered, following their investigation of specific allegations made against individual gardaí.

Mr Guerin, it should be said, operated under many constraints in compiling his report. The terms of reference set for the review were limited in scope. The time set for its completion – eight weeks – was short. It was not possible, with the exception of Sgt McCabe, to interview others central to the various allegations: whether Garda members, civilians, or crime victims. Mr Guerin formed his views from reviewing the files that were made available to him. And there he found “ a near total absence” of any evidence (via written records or otherwise) that Mr Shatter had received submissions or advice from his officials on these issues.

As yet, there is no explanation for this remarkable communications failure within the Department, and between its top officials and Mr Shatter. Some have suggested that to avoid close public scrutiny – via freedom of information requests – of a sensitive aspect of the Department’s role in handling such allegations, that the Department committed little to paper as a means of minimising public disclosure.

The Guerin report has exposed the fault line in the relationship between the Department of Justice and An Garda Síochána, which has already seen both the Minister and the Garda commissioner resign. It greatly strengthens the argument – now accepted by the Government – for the establishment of a police authority, as in Northern Ireland, which is independent of political control. Public trust and confidence in policing and in the administration of justice needs to be restored. Past reforms, including the Garda Síochána Act 2005, have proved inadequate. And further failure is no longer an option, especially in relation to the Department of Justice.